Heterocyclic chromenes and their use in the field of ophthalmic optics
US5754271A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 3, 1996 |
| Grant date | May 19, 1998 |
| Priority date | — |
| Expiry date | Jun 3, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C1/73
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The invention relates to photochromic compounds of general formula: ##STR1## wherein R.sup.a, R.sup.b and R.sup.c is denote hydrogen; alkyl; aryl; OR, SR, COR or COOR, in which R denotes hydrogen, alkyl or aryl, amino of formula NR.sub.1 R.sub.2 in which R.sub.1 and R.sub.2 denote hydrogen, alkyl, cycloalkyl or an aryl; a halogen atom; a mono- or polyhaloalkyl group; or an NO.sub.2, CN or SCN group; n and m denote integers from 1 to 5; p is equal to 1 or 2; and H is a 5-members aromatic heterocycle containing one or more heteroatoms selected from nitrogen, oxygen and sulfur, these heterocyclic nuclei being eventually substituted by one or more alkyl, alkoxy, amino, aryl or aralkyl groups or condensed with a phenyl nucleus, a substituted phenyl nucleus or a 6-members cycloaliphatic nucleus and to their use in ophtalmic optics.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.